Forumers at the GameFAQs message board continue to send their messages of congratulations and thanks to Saiyan Sonic on his achievement. Saiyan Sonic has apparently gone on record with what does happen. From Saiyan, this was posted by another forumer, and is from an AIM conversation:
You get a Green Hill Zone in 3D, it’s really cool and it has old sound effects and stuff. You can only play as sonic though…but it’s still really cool.
Is this it? From what we’ve heard, yes! But we should be getting the save relatively soon, and we’ll tell you what happens.